From ce4835497c20991574fde492ab37ec666563d3e4 Mon Sep 17 00:00:00 2001 From: Amit Daniel Kachhap Date: Thu, 17 Nov 2022 06:37:21 +0100 Subject: [PATCH] ARM: 9270/1: vfp: Add hwcap for FEAT_FHM Floating-point half-precision multiplication (FHM) is a feature present in AArch32 state for Armv8 and is represented by ISAR6.FHM identification register. This feature denotes the presence of VFMAL and VMFSL instructions and hence adding a hwcap will enable the userspace to check it before trying to use those instructions. Reviewed-by: Linus Walleij Signed-off-by: Amit Daniel Kachhap Signed-off-by: Russell King (Oracle) --- arch/arm/include/uapi/asm/hwcap.h | 1 + arch/arm/kernel/setup.c | 1 + arch/arm/vfp/vfpmodule.c | 6 ++++++ 3 files changed, 8 insertions(+) diff --git a/arch/arm/include/uapi/asm/hwcap.h b/arch/arm/include/uapi/asm/hwcap.h index 64f3608e6f1b..3d168d4f2a51 100644 --- a/arch/arm/include/uapi/asm/hwcap.h +++ b/arch/arm/include/uapi/asm/hwcap.h @@ -31,6 +31,7 @@ #define HWCAP_FPHP (1 << 22) #define HWCAP_ASIMDHP (1 << 23) #define HWCAP_ASIMDDP (1 << 24) +#define HWCAP_ASIMDFHM (1 << 25) /* * HWCAP2 flags - for elf_hwcap2 (in kernel) and AT_HWCAP2 diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c index 9841b897d476..d88c1326f529 100644 --- a/arch/arm/kernel/setup.c +++ b/arch/arm/kernel/setup.c @@ -1252,6 +1252,7 @@ static const char *hwcap_str[] = { "fphp", "asimdhp", "asimddp", + "asimdfhm", NULL }; diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c index 70f1e0f4eece..404c4f901132 100644 --- a/arch/arm/vfp/vfpmodule.c +++ b/arch/arm/vfp/vfpmodule.c @@ -845,6 +845,12 @@ static int __init vfp_init(void) isar6 = read_cpuid_ext(CPUID_EXT_ISAR6); if (cpuid_feature_extract_field(isar6, 4) == 0x1) elf_hwcap |= HWCAP_ASIMDDP; + /* + * Check for the presence of Advanced SIMD Floating point + * half-precision multiplication instructions. + */ + if (cpuid_feature_extract_field(isar6, 8) == 0x1) + elf_hwcap |= HWCAP_ASIMDFHM; /* Extract the architecture version on pre-cpuid scheme */ } else { -- 2.11.0